For this problem, we have to set up the formula for the equation first. The equation should help us predict how long would it take to reach a life expectancy of 130 years. Let's start by denoting variable to present them in algebraic equations. Let x be the number of decades, while y is the number of years for life expectancy. The base year used here is 2009 with a life expectancy of 80 years. So, we will expect that 80 is a constant in the expression. We will add to this the number of decades multiplied by 5.4, because it stands for 5.4 additional years per decade. When you write this in an equation, it would be
y = 80 + 5.4x
Now, we substitute y=130.
130 = 80 + 5.4x
x = (130 - 80)/5.4
x = 9.259
Therefore, it would take approximately more than 9 decades. Projecting this amount of time from 2009, the year would be:
Projected year = 2009 + 9 decades * (10 years/1 decade)
Projected year = 2101
It would be in year 2101.